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| author |   Jernej Skrabec <jernej.skrabec@siol.net> | 2019-11-24 18:29:03 +0100 |
|---|---|---|
| committer |   Thierry Reding <thierry.reding@gmail.com> | 2020-01-08 12:47:26 +0100 |
| commit | a7fe985633f927401037d2905df2c9701dff09a1 (patch) | |
| tree | 829a3f157ec3e45e0f28397b3745176069c24f0a /drivers/pwm | |
| parent | pwm: imx27: Unconditionally write state to hardware (diff) | |
| download | linux-dev-a7fe985633f927401037d2905df2c9701dff09a1.tar.xz linux-dev-a7fe985633f927401037d2905df2c9701dff09a1.zip | |
pwm: sun4i: Add an optional probe for reset line
H6 PWM core needs deasserted reset line in order to work.
Add an optional probe for it.
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/pwm-sun4i.c | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c index 581d23287333..487899d4cc3f 100644 --- a/drivers/pwm/pwm-sun4i.c +++ b/drivers/pwm/pwm-sun4i.c @@ -16,6 +16,7 @@ #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pwm.h> +#include <linux/reset.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/time.h> @@ -78,6 +79,7 @@ struct sun4i_pwm_data { struct sun4i_pwm_chip { struct pwm_chip chip; struct clk *clk; + struct reset_control *rst; void __iomem *base; spinlock_t ctrl_lock; const struct sun4i_pwm_data *data; @@ -364,6 +366,22 @@ static int sun4i_pwm_probe(struct platform_device *pdev) if (IS_ERR(pwm->clk)) return PTR_ERR(pwm->clk); + pwm->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL); + if (IS_ERR(pwm->rst)) { + if (PTR_ERR(pwm->rst) != -EPROBE_DEFER) + dev_err(&pdev->dev, "get reset failed %pe\n", + pwm->rst); + return PTR_ERR(pwm->rst); + } + + /* Deassert reset */ + ret = reset_control_deassert(pwm->rst); + if (ret) { + dev_err(&pdev->dev, "cannot deassert reset control: %pe\n", + ERR_PTR(ret)); + return ret; + } + pwm->chip.dev = &pdev->dev; pwm->chip.ops = &sun4i_pwm_ops; pwm->chip.base = -1; @@ -376,19 +394,31 @@ static int sun4i_pwm_probe(struct platform_device *pdev) ret = pwmchip_add(&pwm->chip); if (ret < 0) { dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); - return ret; + goto err_pwm_add; } platform_set_drvdata(pdev, pwm); return 0; + +err_pwm_add: + reset_control_assert(pwm->rst); + + return ret; } static int sun4i_pwm_remove(struct platform_device *pdev) { struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev); + int ret; + + ret = pwmchip_remove(&pwm->chip); + if (ret) + return ret; + + reset_control_assert(pwm->rst); - return pwmchip_remove(&pwm->chip); + return 0; } static struct platform_driver sun4i_pwm_driver = { |